"I talked to a political consultant when I was doing The Adjustment Bureau," he recalled. "He was getting out of the business. He said that when he started out, you'd work for someone you believed in and you'd craft these messages.

"It was all about the nuance. And then we figured out somewhere along the line that you throw [stuff] at the other candidate and it doesn't matter if it's true."

Damon's current film Promised Land tackles the issue of oil drilling, which continues to be a hot button topic in the US political scene.

Promised Land is now playing in the US and opens in the UK on April 19. Watch a trailer below: